The objective of this research is to isolate the as yet unidentified toxin of Atlantic shellfish poisoning caused by the dinoflagellates, Gonyaulax tamparensis, with eventual aims of devising preventive measures or antidotes, and also studying the pharmacological implications of possible therapeutic use. The experiment is planned to take advantage of an immense quantity of toxi clams collected during the large scale cutbreak in 1972 at the New England coast. In a preliminary experiment non-identity of the toxin with saxitoxin, a partial purification scheme has been established. A large quantity extraction(200 kg) is planned to obtain enough toxin for further studies which include the structure elucidation, immunochemical, and pharmacological studies.